10 Thing You Should Never Buy on eBay or Craigslist

10 things you should never buy used

Sometimes the financial or safety risk outweighs the savings. Do you really want to sleep on someone else’s mattress — or take a chance with your child?

Saving money by surfing the internet for bargains is delightful, but you can take it too far.

In my companion piece, “10 things you shouldn’t buy new,” I listed lingerie as one of the items for which you’d best pay retail. There are plenty of other examples where the cost savings don’t justify the risks of buying used:

Laptops. You’re taking a chance when you buy any used computer, but the math really doesn’t work when you’re talking about a unit that’s as prone to abuse and problems as a laptop. They’re more likely to be dropped, banged around and spilled on, simply because they’re out in the world while a desktop computer sits (mostly) safe at home.

That’s why laptops are one of the few products where springing for an extended warranty with free tech support makes sense, in addition to the standard warranty that typically comes when you buy new. Buy used, and you’ll have neither option — along with no idea what maltreatment your laptop has suffered or when the hard drive, optical drive or other important parts will die on you.

Exception: You’re buying a refurbished unit that comes with a warranty. Mobile technology consultant Catherine Roseberry, who writes a column for About.com, said she’s purchased two laptops from companies that refurbished leased corporate computers, and had no problems with either. Both came with 90-day warranties. If you want even more security, buy a laptop that’s been refurbished and certified by the manufacturer.

Car seats. A car seat that’s been in one accident may not protect your child in another. And damaged car seats aren’t uncommon; a survey commissioned by Sainsbury’s Bank in England discovered one in 10 car seats currently in use in that country had been involved in an accident. (The bank is calling for a ban on the sale of secondhand seats.)

Brand-new car seats can often be purchased for as little as $50, and safety technology tends to improve with each year, said Denise and Alan Fields, parents and authors of “Baby Bargains.” That makes getting a new one pretty much a no-brainer.

Exception: You’re getting the car seat from a friend or relative whom you’d trust with your child’s life, because that’s what you’re doing. Still, check with the National Highway Traffic Safety Administration to make sure the model you’re getting hasn’t been recalled.

Regardless of whether you buy new or used, have an expert check your work to make sure the seat is installed correctly. The NHTSA has a list of free inspection sites at its Web site, as does DaimlerChrysler’s Fit for a Kid program, which offers free inspections, regardless of what type of car you drive.

Plasma TVs. Here’s another of those rare cases where you want not only the warranty that comes with the television, but an extended warranty. You’ll want the coverage because if your screen dies, it can cost thousands to fix or replace — sometimes almost as much as it would cost to buy a new TV.

While defect rates have declined from 7% in plasma TV’s early years to about 1% with some of the better models, problems with this technology are still common enough — and repairs expensive enough — that an extended warranty makes sense, said Phil Connor of PlasmaTVBuyingGuide.com.

Exception: If you’re getting such a screaming deal that you don’t really care if the TV blinks out shortly after you get it home.

DVD players. In the previous article, I recommended buying used DVDs, since their quality tends to remain high (unless they have scratches, which are usually pretty easy to spot).

The same is not true of DVD players, however. These have lasers that will eventually wear out and cost more to replace than the unit is worth.

Whenever repairs cost that much, buying new is often advisable. Add to that the fact that prices are constantly dropping while the technology is constantly improving, and buying new becomes a slam dunk.

Vacuum cleaners. Here’s another item that’s particularly prone to abuse and that may cost you more to fix than if you’d simply bought new. Consumer Reports says a good, basic upright can be purchased new for less than $100, and that the fancy features that push prices higher often aren’t worth the extra cost. Just make sure to buy one that you’re comfortable pushing and that has a decent filtration system to prevent dust from kicking back out into the air.

Camcorders. Someday they’ll build a camcorder out of rubber, so that it’ll bounce when you drop it, which is almost inevitable. The damage from a fall may not be obvious when you buy used, but it may soon require a costly repair. Camcorder motors can also wear out and may cost you a couple hundred dollars to replace.

If you want to save money on a camcorder, consider buying last year’s model.

Exception: You’re buying a refurbished model that comes with a warranty. RefurbDepot.com, for example, posts many models that still carry a factory warranty.

Shoes. Poor-fitting shoes can cause everything from bunions to back problems, so don’t buy footwear that’s already been molded by someone else’s tootsies. This is particularly important for kids whose feet are still growing. Shop sales, buy last year’s models, but don’t give in to the temptation to save a buck now that’s going to cost you more in pain and hassles later.

Exception: You’re buying old cowboy boots to turn into lamps.

Mattresses. Think of all the stuff you do on your mattress. Now think of sleeping in someone else’s stuff. Ewwwww.

Unfortunately, you may already be spending the night with other people’s mold, mites, bacteria and bodily fluids. Dishonest retailers sometimes ignore federal requirements that used mattresses be labeled as such, often covering a secondhand cot with new ticking to disguise it. If you want an all-new mattress, the Federal Trade Commission recommends looking for a tag that promises “all-new materials” and requiring that the retailer write the word “new” on the receipt. (That can make it easier to prove your case should you find you’ve been sold a used mattress on the sly.)

There’s also the fact that mattresses aren’t meant to last forever. Even the good ones typically have a life span of just eight to 10 years, and it’s hard to know for sure how old a used mattress may already be.

Exception: When “used” is really almost “unused,” such as a mattress from someone’s rarely visited guest room. Still, you’d really have to trust the buyer to know, and disclose, everything that’s happened on that bed, which is why you’re still probably better off buying new. You shouldn’t ever pay the list price, because haggling is expected. Consumer Reports suggests you need to spend about $800 to get a good-quality queen-size mattress and box spring set. That works out to about 25 cents a night — a small price to pay for cleanliness and comfort.

Wet suits. These spongy coverings tend to lose their ability to keep you warm over time. If you’re a scuba diver, the constant change in water pressure will eventually take its toll.

“As a suit is used, the neoprene compresses and become thinner, losing its thermal properties and buoyancy,” said master dive instructor Gerrard Dennis of Simply Scuba, an online scuba store based in the United Kingdom, where the need for warmth is crucial. “Also, ozone attacks neoprene suits so they become less stretchy and more likely to tear with age.”

If diving, snorkeling or other water sports are your passion, a good wet suit will set you back $100 to $400.

Exception: You’re surfing, rather than diving, exclusively in warm waters. If you’re trying to outfit a growing child and don’t want to pop for a new suit, consider renting from a reputable shop that sanitizes the suits between uses.

Helmets. Like a car seat, a helmet is meant to protect against one accident and no more. A crash typically crushes the foam inside the helmet casing, according to the Bicycle Helmet Safety Institute, so the damage may not be visible. Since you usually can’t tell if a helmet’s ticket has already been punched, you’re smarter to buy new. Kid’s sports and bike helmets retail for about $20; you’ll pay $30 to $40 for the adult size. Motorcycle helmets usually start around $100 and climb steeply from there; you can contain the cost by resisting the fancy paint jobs.

Exception: None. Helmets aren’t that expensive compared to a funeral or a lifetime as a quadriplegic. Spend the money.